SONET transmission signal processing method and SONET transmission signal processing apparatus

Abstract

A VT (Virtual Tributary) size setting section 3 allows selection of the VT size desired by the user of the apparatus by accepting setting data inputted by the user of the apparatus. The VT size comparing section 4 compares the VT size detected at the VT size receiving section 2 with the VT size set by the VT size setting section 3 in order to detect coincidence or noncoincidence. The data outputting section 5 executes the predetermined data processing of data extracted from a SONET (Synchronous Optical Network) transmission signal in accordance with the VT size set by the VT size setting section 3 when the result of the comparison at the VT size comparing section 4 indicates coincidence, but executes error signal processing when the result of comparison at the VT size comparing section 4 indicates noncoincidence.

What is claimed is: 
     
       1. A method of processing a received SONET (Synchronous Optical Network) transmission signal having a synchronization payload envelope capacity which has a first column including data and a first byte which includes bits indicating a VT (Virtual Tributary) size of the data and a second column including only data, comprising the steps of: setting a desired VT size,   detecting the first byte included in the first column,   detecting the VT size of the data included in the first column from the first detected byte,   comparing the detected VT size with the desired VT size, and   executing a predetermined signal processing for the data included in the first column in accordance with the desired VT size when the step of comparing indicates coincidence between the detected VT size and the desired VT size but   executing an error signal processing for the data included in the first column when the step of comparing indicates noncoincidence between the detected VT size and the desired VT size.   
     
     
       2. A SONET transmission signal processing method according to claim 1, which further comprises the steps of: executing the predetermined signal processing for the data included in the second column in accordance with the desired VT size when the step of comparing with regard to the first column received prior to the second column indicates coincidence between the detected VT size and the desired VT size but   executing the error signal processing for the data included in the second column when the step of comparing with regard to the first column received prior to the second column indicates noncoincidence.   
     
     
       3. A SONET transmission signal processing method according to claim 1 wherein the error signal comprises changing all of the data of the first column except for the first byte to "0" or "1." 
     
     
       4. A SONET (Synchronous Optical Network) transmission signal having a synchronization payload envelope capacity which has a first column including data and a first byte which include bits indicating a VT (Virtue Tributary) size of the data and a second column including only data, comprising: VT size setting means for setting a desired VT size,   VT size detecting means for detecting the first byte included in the first column and determining the VT size of the data included in the first column from said first byte,   comparison means for comparing the VT size detected by the VT size detecting means with the desired VT size set by the VT size setting means, and   data outputting means for executing a predetermined signal processing for the data included in the first column in accordance with the desired VT size set by the VT size setting means when an output signal of the comparison means indicates coincidence between the detected VT size and the desired VT size, and for executing an error signal processing of the data included in the first column when the output signal of the comparison means indicates noncoincidence between the detected VT size and the desired VT size.   
     
     
       5. A SONET transmission signal processing apparatus according to claim 4, wherein the data outputting means executes the predetermined signal processing for the data included in the second column in accordance with the desired VT size set by the VT size setting means when the output signal of the comparison means with regard to the first column received prior to the second column indicates coincidence between the detected VT size and the desired VT size, but executes the error signal processing of the data included in the second column when the output signal of the comparison means with regard to the first column received prior to the second column indicates noncoincidence between the detected VT size and the desired VT size.   
     
     
       6. A SONET transmission signal processing apparatus according to claim 4, wherein the error signal processing comprises changing all of the data of the first column except for the first byte to "0" or "1". 
     
     
       7. A SONET transmission signal processing method according to claim 2, wherein the error signal processing comprises changing all of the data of the second column to "0" or "1." 
     
     
       8. A SONET transmission signal processing apparatus according to claim 5, wherein the error signal processing comprises changing all of the data of the second column to "0" or "1."